Investment Securities, AFS and HTM Securities Amortized Costs and Fair Values (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	$ 5,521,236	$ 5,367,813
Debt Securities, Available-for-Sale	5,514,456	5,397,563
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(20,846)	(11,551)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	14,066	41,301
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	3,570,901	3,602,576
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	1,294	3,488
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(449,746)	(415,070)
Debt Securities, Held-to-Maturity, Fair Value	3,122,449	3,190,994
US Treasury Securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	996	996
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	11	19
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	0	0
Debt Securities, Held-to-Maturity, Fair Value	1,007	1,015
US Treasury Securities | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	996	996
Debt Securities, Held-to-Maturity, Fair Value	1,007	1,015
US Treasury Securities | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Fair Value	0	0
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	3,063	3,063
Debt Securities, Available-for-Sale	3,020	3,044
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(44)	(20)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	1	1
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,618,922	1,628,088
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	1,212	3,070
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(157,227)	(123,856)
Debt Securities, Held-to-Maturity, Fair Value	1,462,907	1,507,302
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	3,020	3,044
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,618,922	1,628,088
Debt Securities, Held-to-Maturity, Fair Value	1,462,907	1,507,302
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	3,020	3,044
Debt Securities, Held-to-Maturity, Fair Value	1,462,907	1,507,302
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	0
Debt Securities, Available-for-Sale	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	298,196	302,817
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(44,962)	(43,990)
Debt Securities, Held-to-Maturity, Fair Value	253,234	258,827
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	92,852	95,977
Debt Securities, Available-for-Sale	91,828	95,046
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(1,036)	(950)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	12	19
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Debt Securities, Held-to-Maturity, Fair Value	0
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	91,828	95,046
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	91,828	95,046
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	63,257	283
Debt Securities, Available-for-Sale	63,301	269
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(187)	(14)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	231	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Debt Securities, Held-to-Maturity, Fair Value	0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	63,301	269
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	63,301	269
Other Debt securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	3,000	3,000
Debt Securities, Available-for-Sale	2,998	2,998
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(2)	(2)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	0	0
US Government Sponsored-Enterprise Insured Loans | Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	136,572	134,142
Debt Securities, Available-for-Sale	131,583	129,863
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(5,881)	(5,493)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	892	1,214
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	811,047	823,630
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	38	165
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(129,239)	(127,333)
Debt Securities, Held-to-Maturity, Fair Value	681,846	696,462
US Government Sponsored-Enterprise Insured Loans | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	131,583	129,863
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	811,047	823,630
Debt Securities, Held-to-Maturity, Fair Value	681,846	696,462
US Government Sponsored-Enterprise Insured Loans | Residential Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	131,583	129,863
Debt Securities, Held-to-Maturity, Fair Value	681,846	696,462
US Government Sponsored-Enterprise Insured Loans | Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	17,864	17,959
Debt Securities, Available-for-Sale	16,936	16,958
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(928)	(1,001)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	761,410	763,370
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(111,600)	(113,004)
Debt Securities, Held-to-Maturity, Fair Value	649,810	650,366
US Government Sponsored-Enterprise Insured Loans | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	16,936	16,958
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	761,410	763,370
Debt Securities, Held-to-Maturity, Fair Value	649,810	650,366
US Government Sponsored-Enterprise Insured Loans | Commercial Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	16,936	16,958
Debt Securities, Held-to-Maturity, Fair Value	649,810	650,366
Government National Mortgage Association (GNMA) [Member] | Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	5,091,918	5,000,015
Debt Securities, Available-for-Sale	5,096,659	5,039,829
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(8,189)	(253)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	12,930	40,067
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	38,021	39,123
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	33	82
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(2,365)	(2,321)
Debt Securities, Held-to-Maturity, Fair Value	35,689	36,884
Government National Mortgage Association (GNMA) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	5,096,659	5,039,829
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	38,021	39,123
Debt Securities, Held-to-Maturity, Fair Value	35,689	36,884
Government National Mortgage Association (GNMA) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	5,096,659	5,039,829
Debt Securities, Held-to-Maturity, Fair Value	35,689	36,884
Government National Mortgage Association (GNMA) [Member] | Commercial Mortgage-Backed Securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	112,710	113,374
Debt Securities, Available-for-Sale	108,131	109,556
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(4,579)	(3,818)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	42,309	44,552
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain	0	152
Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss	(4,353)	(4,566)
Debt Securities, Held-to-Maturity, Fair Value	37,956	40,138
Government National Mortgage Association (GNMA) [Member] | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	108,131	109,556
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	42,309	44,552
Debt Securities, Held-to-Maturity, Fair Value	37,956	40,138
Government National Mortgage Association (GNMA) [Member] | Commercial Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-Sale	108,131	109,556
Debt Securities, Held-to-Maturity, Fair Value	$ 37,956	$ 40,138